Dippeb tbip



P. s. STEVENS DIPPER TRI P 6 2 9 1 7 2 V. l H J Original Filed 192575445 572mm. IN VEN TOR.

A TTORNEYS.

Reissued Jul 21, 1926.

UNITED STATES PATENT OFFICE.

PAUL 8. STEVENS, 01' SOUTH MILWAUKEE, WISCONSIN, ASBIGNOB TO BUCYBUS COMrm, SOUTH MILWAUKEE, WISCONSIN- DIPPEB TRIP.

Original Io. 1,574,768, dated larch 2, 1926, Seriallio. 70,585, fliedIovember at, 1985. Application or reissue filed April 14, 1988. serialNo. 102,002.

This invention relates to excavating machinery and more particularly tothat type of excavating machine commonly known as a power s ovel, theprimary o'bject of the invention being to provide novel means forcausing the bottom of the dip r of such shovel to be released fordumping the load.

-In the usual construction of power shov- 1' els, the excavating dipperis mounted on the end of a air of dipper-sticks, or handle, which isdesigned to reciprocate with respect to, and swing about, a certainpoint on the boom of the excavator. The dipper is l provided with ahinged bottom, WlllCh is releasably held closed by means of a latchmechanism.

In the usual construction of a dipper trip, a rope extends from thislatch to the opera-tors position on the main platform of the machine. Invariations of this device, particularly when power is employed to do wthe tripping, elaborate means have been devised to compensate for thereciprocating and swin 'n movements of the dipperhandle. giic acomplicated device can be avoided, if a feasible means is found forjmounting the tripping motor on the dipperhandle itself.

In an electrical excavator, where electric, ity is the only poweravailable, new complications are introduced,due to the employment of arotating motor to supply the force for the tripping.

In devices in which this motor is mounted on the main platform, a lightcurrent must continuously paw through it, to take up the slack in thetrip rope as the dipper-handle swings and reciprocates. This currenttends 40 to overheat and burn out the motor.

And, re tor, there as always been required an elaborate electricalmechanism to cut out the current the instant that tri ping has been 46accomplished. Otherwise t e motor will stall; and, unless specialoverload relays are provided to revent holding a high torque with fullv'o tage, this would burn out the motor. Furthermore the motor will bebrou t up to stal with such a jar, that the y-wheel energy uilt up inthe rotating rdless of the location of the moarmature will wear out thedrum and ropes and chains, and will even bend the motorshaft. 1

It is one of the objects of my invention to do away with these evilsi byproviding a rotating motor which wi actuate a dipper trip without thepossibility of overheating or stalling, and without the need ofelaborate control. Other objects and advanta es of my invention will beevident to t ose skilled in the art, and therefore need not be hereinmore specifically set forth. r

The invention consists in the novel parts and in the combinations andarrangements defined in the appended claims and of which one embodimentis exemplified in the.

di r trip in place.

Figure 3 is an enlarged side elevation of the motor and related parts ofmy dipper mechanism shown in Figure 1.

trip he di per 1 has a. swinging bottom 2 held b t e hinge 3. The ttomis held closed y the latch 4 which slides in guides 5 and engages alatch-keeper 6.

The latch may be induced to engage the latch-keeper by means of gravity,or any.

' other adequate actuating means.

The dipper 1 is secured at the end of dipper-hand es7.

In the these han les are for engagement wi rticular exem lificationshown, rovi ed with racks 8 shipper-shaft pinions 9, mounted forrotation on'the boom 10.

The rotation of these inions by any suitable means (not shown thruststhe dipper in and out. In the particular exenip ification shown, thedipper 'and handle are swung about the shipper-shaft by means of thehoist-rope 11, w 'ch passes over the sheave 12 atthe point of the boom,and

' tom may be substitut v shaft 16 and lever 18. The connecting-rod ,edon one of the handles 7. The word drum, as used herein, is intended tomean any member, such as a drum or shaft, which rforms-the functions ofa drum. The word wheel, as used in the claims herein, shall be taken tomeanany rotatable element including a centrally pivoted disc, a gear orpinion, a crank-arm, a cam, or an eccentric. And the word center asreferring to such wheel shall be taken to mean the center of rotation ofsuch wheel. The connecting-rod 19, although shown as one integral iece,may be'made of parts permitting suc ad- 'ument in the length of thisunit as may required. An appro riate leverage sys- "19 may be madeflexible.

The ar is rotated by a pinion 21 moun 'on the end of the shaft of anelectric motor 22. I

This motor is electrically connected to the wer source b uctor 23, a ca1e take-u -box 24 of any appropriate design, a con uctor extending tothe operators position, and a switch of any appropriate design (notshown) under the control of the operator.

For the pa s of the following geometrical explanation, I have letteredfour points in Fi re 3 as follows A is the center of the whee 20; B isthe point of connection of vthe connectin -rod 19 and the wheel 20; C

is the point 0 connection of the connectingrod 19 and the lever 18; D isthe center of" rotation ofthe lever 18.

The parts 18, 19 and 20 are so proportioned and the points A and D areso located ,that AB is appreciably less than DC; and I so that, if of Cand AD, either one exceeds the other, the difference between them shallbe appreciably less than DC minus AB. A

' It will be readily seenthat, when the dipper 1 has been hoisted andextended to the roper tion for dumpin the o eratdican the same b closingt e switch above referred to. e motor 22 will then rotate,thus rotatingthe pinion 21 and the gear 20. The rotation of the gear 20 willreciprocate the connecting-rod 19,

thus oscillating the lever 18 back and forth. between its two positionsas shown in Fig.-.

ure 3, and thus alternately winding up and unwinding the chain 15 aboutthe rod 16.

for the chain 15,

means of a flexible con- With each winding up of the chain 15, the latch4 will be disengaged from the latchkeeper 6, thus permitting the di perbottom 2 to swing downward in a cloc isev direction and dischargethecontents of the dip- It will be. readily seen that, no matter how longthe operator holds the switch closed, and thereby keeps the motor 22running, the chain 15 can not be wound up more than a certainpredetermined amount, and that therefore there is no danger of stallingthe motor or injuring any of the parts.

Although one particular embodiment of my invention has been shown, I donot intend to be limited thereto. It is within the scope of my inventionto employ other of rotating motor than those actuate by electricity, andto employ other intermediate connections between the latch and the motorthan those shown and described, or suggested, herein.

Having now particularly described and illustrated one form of myimproved dipper trip, I claim;

1. In a dipper trip, the combination of a dipJJer-han e, an excavatingdi r on em handle, a dump-door to said lpper, a latch for said door, alatch-keeper for said han e, a chain to retract said-latch from PBS.

latcldii a drum 'journally mounted in saidv said latchkeeper andextending from said i v latch to said drum and wound about said theradius distance from the point of connection of the connectin -rod andwheel to the center of said whee being appreciably less than the. radiusdistance from the point of connection of the connecting-rod and lever tothe center of rotation of said lever; and the difference between thelength of the connecting-rod and the distance from the center of saidwheel to the center of rotation of said lever being'ap reciably lessthan for said door, a latch-keeper for said latch,

-kee er and associated withsaid latch and sai drum' and wound about saiddrum, a lever to rotate said drum, an electric motor mounted on saiddipper-handle, a wheel rotated by said motor, and aqconnectin memberconnecting said wheel and sai lever; the radius distance from the int ofconnection of the connecting mem rand wheel to the center'of said wheelapreciably less than theradiu's distance oi n the oint of connection ofthe connecting mem r and lever to the center of rotation of said lever;and the difference between the length of. the connecting member and.thedistance from the center of said wheel to the center of rotation of saidlever being appreciablv less than the difference of said radii.

3. In a di per trip, the combination of a dipper-hand e, an excavatingdipper on said handle, a dump-door to said dipper, a latch for saiddoor, a drum journally mounted in said handle, a flexible member tounlatch said latch and associated with said latch and said drum andwound about said drum, a lever to rotate said drum, a power elementmounted on said dipper-handle, a wheel rotated by said power element,and a connecting member connecting said wheel and said lever; the radiusdistance from the point of connection of the connecting member and wheelto the center of said wheel being appreciably less than the radiusdistance from the int of connection of the connecting mom I and lever tothe center of rotation of said lever; and the difference between thelength of the connecting member and the distance from the center of saidwheel to the center of rotation of said lever being ap reciably lessthan the diiference of said ra ii.

4. In a di per trip, the combination of an excavati pper, a'dump-door tosaid dipper, a la mounted in fixed relation to said dipper, a

' flexible member to unlatch said latch and associated with said latchand said drum and wound about said drum, a lever to .rotate said drum,an electric motor mounted in fixed relation to said dipper, a wheelrotated by said motor and connecting means connecting said w eel andsaid lever; the radius distance from the point of connection of theconnecting means and wheel to the center of said wheel bein appreciablyless than the radius distance rom the point of connection of theconnecting means and lever to the center of rotation of said lever; andthe difference between the length of the connecting means and thedistance from the center of said wheel to the center of rotation of saidlever being a preciably less than the difference of said ra 'i 5. In adipper trip, the combination of an excavating dipper, a dump-door tosaid dipper, a latch for said door, a drum journal mounted in fixedrelation to said dipper, a

flexible member to unlatch said latch and associated with said latch andsaid drum and v 1 to said dipper, a wheel rotated by said motor andconnecting means connecting said wheel and said lever; said connectingmeans, wheel and lever being so proportioned and disposed that acomplete rotation of said wheel for said door, a drum journallyoscillates said lever through merely a certain predetermined arc.

6. In a dipper trip, the combination of a dipper-handle, an excavatingdipper onisaid handle, a dump-door to said dipper, a latch for saiddoor, a lever mounted on said handle, means to unlatch said latch andassociated with said latch and said lover, a

between the length of the connecting means and the distance from thecenter of said wheel to the center of rotation of said lever beingappreciably less than the difference of said radii.

I 7. In a dipper trip, the combination of an excavating dipper, adump-door to said dipper, a latch for said door, a lever mounted on aivot which bears a fixed relation to said dipper, means to unlatch saidlatch i and associated with said latch and said lever, an electric motormounted in fixed relation to said dipper, a wheel rotated by said motor,and connecting means connecting said wheel and said .lever; the radiusdistance from the point of connection of the connecting means and wheelto the center of said wheel being appreciably less than the radiusdistance from the point of connection of the connecting means and leverto the center of rotation of said lever; and the difierence between thelength of the connecting means and the distance from the center of saidwheel to the center of rotation of said lever being appreciably lessthan the difl'erence of said radii.

' 8. In a dip r trip, the combination of an excavating. ipper, adump-door to said dipper, a latch for said door, a lever mounted on apivot which bears a fixed relation to said dipper, means to unlatch saidlatch and associated with said latch and said lever, a motor mounted infixed relation to said dipper, a wheel rotated by said motor, and

a connecting-rod connecting said wheel and said. lever; saidconnecting-rod, wheel and lover being so proportioned and disposed thata complete rotation of said wheel oscillates said lever through merely acertain predetermined arc.

9. In a di r trip, the combination of an excavating 1 per, a dump-doorto said dipper, a latch or said door, a lever mounted on a pivot whichbears a fixed relation to said dipper, means to unlatch said latch andassociated with said latch and said lever, a motor mounted in. fixedrelation to 'said dipper, a wheel rotated 'by said motor, and connecting-means connecting said wheel and said lever; said connecting means,wheel and lover being so proportioned and disposed that a completerotation of said wheel oscillates' said lever through merely a certainpredetermined are.

10; In a dipper trip, the combination of an excavatin dipper, adump-door to said tated by said motor, an means; said wheel and saidmeans being i 10 dipper, a late for said door, a latch-keeper for saidlatch, means to retract said latch from said latch-keeper, a motormounted in fixed relation-to said di per, a wheel roactuatin S8.ld

so proportioned and dis d that a comp ete rotation of said whee merelyretracts said latch a predetermined distance.

11. In a dip r trip, the combination of 20 an excavating ipper,a'dump-door to .said

dip a latch for said door, means to on-f said latch, a motor mounted infixed late relation to said dipper, a wheel rotated b said'motor, andactuating said means; sai wheel and saidmeans being so proportioned anddisposed that a complete rotation of said wheel actuates said latch notappreciably more than enough to unlatch it.

12. In a dip er tnp, the combination of an excavating i per,.a dump-doorto said dip r, a latch f r said door, means to unlatc said latch, amotor mounted in fixed relation to said dipper, a wheel rotated b saidmotor, and actuatingsaid means; sai wheel and said means being soroportioned and disposed that said wheel is me to rotate continuouslyand that rotation of said wheel actuates said latch not appreciably morethan enough to unlatch it.

- PAUL S. STEVENS.

